<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .pp{
            width: 200px;
            height: 200px;
            background-color: yellowgreen;
        }
    </style>
</head>
<body>
    
</body>
<script>
    var box = document.createElement("div");
    box.innerText = "12345";
    box.className = "pp";
    // box.style.backgroundColor ="yellow";
    // box.style.width= "200px";
    // box.style.height = "200px";
    
    document.body.appendChild(box);
    console.log(box);
</script>
</html>